Postfix-Courier-Maildrop-Centos7

Hi
After more than a week to get a my mail server running, I think I need help!
I follow a mixup of perfect server CentOS 7 (Apache2, Dovecot, ISPConfig 3) and (Apache2, Courier, ISPConfig 3).
I have uninstall dovecot before install courier (various way try, rpmbuild, from scratch with default, follow this guide http://www.phparchitecture.com/howto_show.php?id=2)
pop3d, imapd, postfix up and running...
Unable to send an email or received email.
email server is master.mydomain
I try to send from another smtp to virtualhostdomain : "mailbox non-existent"
I try from smtp master.mydomain and some others combination.
I try with telnet master.mydomain 25 : connect, auth login work, message is queue... Nothing else after...
There are folders in /var/mail/username (username as in passwd)
There are folders in /var/vmal/virtualhost/usermailbox
Can you help? What your need from my config?
Anything else work fine in ISPConfig3 (web, dns, etc) even with a slave machine. It's very a big job done!
(feature request : template for mailbox and more explication for package section)
Thank you very much... It's begin to be late in my planning...

Testing from roundcubemail work well!
Send from [email protected] to smtp master.mydomain to:[email protected] CC:[email protected] (in other mailserver)
Finally, there is just one bug. When I try to send an email from email client. (from other smtp oy postfix)
Sending [email protected] (by other smtp) respond "resquest action not taken; mailbox unavailable or not local. Please check recipient and try again.
Pop3 and imap work well!

Hi
Any help??
My mail server don't accept any mail from other mail server (from an email to a virtualhost email) : reply "mailbox unavailable or not local".
And I can't connect from mail client (thunderbird) directly to stmp server to sned email (from virtualhost to any other email).
Please help with postfix configuration!